1. Field of the Invention
The present invention relates broadly to apparatus for the non-invasive testing of underwater timepieces used by SCUBA divers and the like. These timepieces are acquired by the diver with disclosed depth/water pressure resistance limits indicated to the diver by the manufacturer. After watch battery replacement or necessary repair, it is essential for continued safe use and watch movement protection to ensure the original claim of water resistance. This novel invention accomplishes this requirement quickly and efficiently without timepiece disassembly or dangerous movement exposure to water by simple and direct observation.
2. Description of the Prior Art
Testing sealed devices and apparatus for possible leakage of fluids or gases into or out of such apparatus is old and well known in the art. Some apparatus use the pressure difference between the device to be tested and that of the fluid or liquid into which the device is immersed to immediately produce tell-tale bubbles which are visually apparent to the individual observer performing the test. A variety of such testing devices and others are disclosed in the following patents:
U.S. Pat. No. 2,055,568 describes a relatively cumbersome and complex structure in which a watch to be tested is suspended, totally immersed, in a liquid within a transparent receptacle. Means is provided to create a vacuum in the receptacle above the liquid level such that any leakage of air from the watch would create bubbles which may be observed by the test operator. This structural arrangement and testing method continuously and dangerously exposes the watch to possible liquid invasion throughout the test, as well as the possible filling of the watch case with liquid as a result of the vacuum employed with the test. In addition, the test apparatus does not provide a simple and easy method for quickly removing the watch case from the liquid (in case of a faulty seal) to avoid destruction of the movement by the liquid. Obviously, this is not a completely safe procedure for use with delicate and complex watch movements.
U.S. Pat. No. 3,517,547 describes a two stage or two step type watch testing procedure wherein the watch to be tested first has its crown removed after which a structural bore is fitted around the watch stem tube. The watch is then pressurized by a hand pump and any escape of air is noted by movement of the pressure pump. The watch is then immersed in a testing liquid, for example, water or water and alcohol mixed, and visibly checked for the formation and/or escape of air bubbles due to possible leaks in the case or stem of the watch. This apparatus is not a completely sealed member but relies on an integral, attached pressure pump for pressurizing the interior of the watch through the stem tube of the watch after removal of the crown from the watch. First, the complex design variances of lock down crowns, screw down crowns and stem/crown guards requires an extensive bore assembly or an extremely large set of nozzles in order to be able to test all types and styles of the growing sport watch market. This is very expensive and not efficient time-wise. Second, the test is self defeating since reassembly of the watch crown is required, thus negating the purpose of the test. U.S. Pat. No. 3,991,622 describes a complex and very sophisticated electromagnetic/electromechanical strain detection apparatus for detection of strain occurring at the surface of the object in a test container when subjected to a varied pressure. Although this structural arrangement is illustrated and described as used for testing wrist watches, it would appear to be ultra complex, obviously delicate and much too expensive and difficult to use for the average .proprietor of a watch or jewelry shop or even for a proprietor which deals in SCUBA diving timepieces. Also, supposing a leak to be discovered, there is no indication of its location.
U.S. Pat. No. 3,355,932 relates to apparatus for gas pressure testing of watches and requires two different container vessels (one is a test tank and the other is a comparator tank) and two different watches plus assorted valves and a pressure gauge for pressure indication and control. Air is first pumped into the test container by means of a small hand pump. A series of time-consuming tests are then required and performed. In one test, disassembly of the watch under test is also required, which makes the test self-defeating.
Patent DT 2,815,394 relates to a testing chamber for watches in which a watch to be tested is first covered completely with a plastic coating. The pressure in the test chamber of the test device is reduced to a given value creating a pressure differential between the interior of the watch case and the interior of the test chamber. This difference in pressure will cause a bubble of air to form in the plastic coating at the site of any air leak in the device being tested.
Patent 209,379 (Switzerland) illustrates and describes a transparent container in which a watch is suspended immersed in a liquid, for example, water. A threaded hand turned screw applies pressure to the contents until air bubbles appear around the watch case. The apparatus is complex and awkward to use and appears to suffer from the obvious requirement of hand manipulation.